<template>
  <div>
    <router-link
      tag="div"
      to='/'
      class="header-abs"
      v-show="showAbs"
    >
      <div class="iconfont header-abs-back">&#xe624;</div>
    </router-link>
    <div
      class="header-fixed"
      v-show="!showAbs"
      :style="opacityStyle"
    >
      <router-link to="/">
        <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
  </div>
</template>
<script>
export default {
  name: 'Header',
  data() {
    return {
      showAbs: true,
      opacityStyle:{
          opacity:0
      }
    }
  },
  methods: {
    handleScroll: function () {
    const top = document.documentElement.scrollTop
      if (top >60) {
        this.showAbs = false
        let opacity=top/140;
        opacity = opacity>1?1:opacity;
        this.opacityStyle={opacity}
      } else{
        this.showAbs = true
      }
    }
  },
  activated() {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated(){
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>
<style lang="stylus" scoped>
@import '~styles/varibles.styl';

.header-abs {
  position: absolute;
  left: 0.2rem;
  top: 0.2rem;
  width: 0.8rem;
  line-height: 0.8rem;
  text-align: center;
  height: 0.8rem;
  border-radius: 0.4rem;
  background: rgba(0, 0, 0, 0.8);

  .header-abs-back {
    color: #fff;
    font-size: 0.4rem;
  }
}

.header-fixed {
  z-index 2
  overflow: hidden;
  position: fixed;
  height: 0.86rem;
  top: 0;
  left: 0;
  right: 0;
  line-height: 0.86rem;
  text-align: center;
  color: #fff;
  background-color: $bgColor;
  font-size: 0.32rem;

  .header-fixed-back {
    width: 0.64rem;
    position: absolute;
    top: 0;
    left: 0;
    text-align: center;
    font-size: 0.4rem;
    color: #fff;
  }
}
</style>

